Retort with revolving hearth



Sept. 20, 1932. c. AB-DERHALD EN RETORT WITH REVOLVING HEARTH 2 Sheets-Sheet 1 Filed May 18. 1928 Charhs 9 fierl/a 'A'TTQ RN aY's.

p 1932- c. AB-DER-HALDEN 1,878,531

RETORT WITH REVOLVING HEARTH Filed May 1a. 1928 2 Sheets-Sheet 2 Patented Sept. 20, 1932 CHARLES AB-DER-HALDEN, OF NANCY, FRANCE, ASSIGNOR TO SOCIETE POUR LEX- IPLOITATION DES PROCEDES AB-DER-HALDEN, OF PARIS, FRANCE I RETORT WITH REVOLVING HEARTH Application filed May 18, 1928, Serial No. 278,669, and in France April 17, 1928. p

The invention relates to retorts with revolving hearth andmore particularly to revolving hearths of retorts for the continuous carbonization of'carbonaceous materials at low temperature.

It has already been proposed to provide retorts of this kind, in which the material is moved upon the revolving hearth plate by means of radially arranged vanes or plates of variable inclination, by which the material is moved radially on said hearth, provision being made of a set of stationary rakes which stir the material during its travel upon the hearth. 7

Experience has shown that with such adevice the thickness of thelayer of material-to be carbonized increases from the centre to the periphery of the hearth. This is chiefly detrimental-in the case of the carbonizati on at low temperature, sincethe speed'of carbonization much depends upon the thickness of the layer of material to be carbonized. Moreover, some kind of fuels have a tendency to cake and, for a given thickness of the layer, the material is converted into a conglomerate which opposes the circulation of said material upon the hearth; I

V The invention has for. its object to avoid these defects and to provide a device by which the material will be distributed with a uniform thickness throughout the hearth. The invention has also for its object to provide a device by which the speed of circulation of the material from the centre to the periphery of the hearth, or'vice-versa, may be controlled and accurately adjusted. A further object of the invention consists in providing a retort with revolving hearth especially designed for the carbonization of solid fuels having a tendency to agglomerate and, for this purpose, the material which travels upon the hearth is separated by a spiral furrow, instead of the material from caking.

Further features and advantages of the invention willgbe specified inthe following description with reference to the appended drawings which shows, by way of example, an embodiment of the invention in the case of a retort having two revolving hearths, one of forming a continuous layer, thus preventing As shown in the drawings, the retort come prises two revolving hearth plates 1 and 2. se-

cured to a common vertical shaft 3, which latter may be driven in rotation by means of a suitable gearing 4;. j I

The revolvinghearth 1, which is designed for the drying of the material, is rotatable within a chamber adapted to be passed through by the hot gases from a combustion chamber 5, and connected with a stack 6. V The revolving'hearth 2, which serves for the carbonization, is rotatable in a chamber heated from the outside by the combustion gases from the combustion chamber 5, and carries on its under face a circular flange 7, which engages an annular groove 8 filled with a'suitable materiahthe latter being fluid enough to allow the rotation of the hearth, although being sufficiently compact, in order to constitute a gas-tight joint between the chambers above and below thevhearth.

The material to be carbonized passesfrom the revolving hearth 1 to the revolving hearth 2 through a chimney or hopper 10, which extends through a double cover 9 and ends at a small distance above the hearth 2.

The combu stion gases proceeding from the combustion chamber 5 are circulated in the direction shown by the arrows in Fig. 1. Said gases first pass through the chamber below the hearth 2, then flow through suitable flues 11 into the space comprised between the two covers 9, thence through a flue 12 into the space above the hearth 1 Said gases then pass through a flue 13 into the chamber below the hearth 1 whence they are discharged into the stack 6 through a flue'l l. The flue '12 is provided with a valve or register 15 by which the amount of hot gases passing above the drying hearth 1 may be adjusted at will.

The material to be carbonized. is fed to the retort by means of a hopper 16and drops upon the hearth l. Aset of vanes or plates 17 (Fig. 2), inclined upon the diameter of the hearth, causes the material upon the hearth to travel radially toward the centre of the hearth. Said plates'are pivoted to their support. andfthe angle which; they with respect to the direction of rotation may be material which travels upon the hearth'and break down the portions oi the: mass out ma terial which may have agglomerated.

The materiali thern drops; through:the'vertical chimney 10 upon the lower hearth 2 which is provided with a set oi? ar I ranged as will be hereinafterdescribed A stationary plate is so disposed as to take off the desiredamount of earhon-ized imaserial and to cause it to drop" through a discharge chimney or chute 23 into a'serew conveyor 24,- dispOsedE at the lower enchthereot.

The volatile products ,distilled'ofl' during the carhon-ization' are discharged through a tube 25 secured to the cover- 9" and opening into a gas collector- 26L 7 I It warts noted th t the portion or" the material to'be dried which rests upontheup per hearth Lfand whichis r'noved'hy one of theplates or vanes, forms a small'heap- Whichis broken down when passing under the rakes howeversa-id heap preserves substantially the same position upon the hearth; When the latter has turned throu'ghg a complete revolution, the materialengages behind the sameplate or vane-and a further radial displacement is only possible, providedthat a further amount ofmaterialis added to-sai'd heap and increasesits width to aisuflicient extent in order that its nat'urat slope reach the following plate'or vane; v I, l

- @onsequently, the thicknessof the material to becarhonized increases frox-n thecentre of the carbonizationhearth toward: the periphery; As above stated; this; is chiefly detrimental inthe case off 1 w= temperature carboniz'ation', where the speedl ofi the operation dependsto a l 'arge extent: upon the thick ness of the layer of material. 6n the other hand", some caliing fuels, for a given thickness, form'a couglomeratewhi'ch opposes the movement on; the hearth.

These defects areohvi'atedl hy provision, in combinationwith the hearth 2', of. the

plate or vane arrangement according to the invention, in which the plates are disposed along-two diameters ofthe hearth at least and forms a splral. curve in such manner that material which is. movedbyone of plates toward the centre orthe periphery'is brought into the path of the successive plate engages the latter. Moreover, the plates term: determined angles with the tangents toth-e spiral, amdsaidanglest may beadjusted according to-the desired rate of discharge of the material from the hearth.

In the embodiment shown in the drawings,

' the material to be carbonized, which is delivered from the centralhopper 10, is spread over: the hearth 2; by the delivering plate or vane 29in an amount which is determined by the angle a formed by said plate and the directionwoii rotation; said angle may be adfjustedffrom the outside by means of a control rod 450'. Every portion of the material spread-,- overwthe hearth by the plate 29 is moved radially the plates 30, 30, 30',

30 ';,successively, and is thus brought behind the plate 31. As before,this portionof material is progressively moved" towardi theperiphery bythe successive" platesfilf,31,317 etc; until it reaches the: outer" plate- 35, by which itis-taken ofi' and'drop's into.- the chute 23. The several plates 30, 31,;ete.-.;arepivoted to their sup-portend theirangle-na'ay be adjusted from the outside by means of rods 41, 42, 43, 44 Similarly, the angle of plate maybe adjusted by means of arod 455:. Due to the above arrangement oisthe plates,-

the distribution of the material is made uni form throughout the surface oi the hearth; Furthermore, the -mater1alnto= be carbonized; instead of being spread in acontinuouslayer,

forms on the hearth plate a substantially spiral heap, the externalisurface ofi which: ad:- lows the ready separation at tier gases; Finally, the material to hecarbonized describes a directly"controllable number of revolutions The speed of rotation being, known, itfis possible: todetermine with" a "roo great accuracy the duration of thev operation.

The device above described is particularly adapted for'the carbonizationof (raking coals whose carbonization would'he practically inrpossihl'e with plate arrangement as" de scribed with reference to the drying-liearthli j Obviously, the invention is not strictly limited to its use in c'arborrizationretorts and itimay be employed in all c ases' where it is desirable to distribute" the material to be treated at a uniform thickness, to increase to award; mum the surface of contact of the material with the atmosphere of: theretort, and to ac curately control the time during which: the material remains upon the hearth Having now descrihed'my inventiomiwhat I claim as new and desire to secure by LettersP'atent is: i

1; In a retort, a revolvable hearth plate, means for rotatingsaid'hearth plate about a vertical axis, a stationary support above said hearth plate, a numberot vanesfor" guiding the material to be treated" pivoted on :said support and'having their'l'ower adjacent said hearth plate and adapted'toassume diiierent angular positions with rela" tion to azradial direction from the'center'of said hearth plate,'andf rods pivotedontal'l of thevanesand'extending through the retort on the outside of said retort, whereby the angular position of said vanes may be regulated from stationary points on the outside of the retort during the rotation of said hearth plate.

2. In a retort, a revolvable hearth plate, means for rotating said hearth plate about a vertical axis, stationary supports in radial directions above said hearth plate, a number of studs on said supports disposed perpendicularly to said hearth plate and along a spiral line on said hearth plate, whereby said studs are at different distances from the center of said hearth plate, vanes for guiding the material to be treated pivoted on said studs and having their lower edges adjacent said hearth plate and disposed angularly with relation to a radial direction from the center of said hearth plate.

3. In a retort, a revolvable hearth plate, means for roating said hearth plate about a vertical axis, a feeding hopper for the material to be treated having its lower end near and above said hearth plate, a discharge conduit for said material under said hearth plate, said feeding hopper and said discharge conduit being disposed the one near the centre of the hearth plate, and the other near the periphery of said hearth plate, a stationary support above said hearth plate, vanes for guiding the material carried on said support and having their lower edges adjacent said hearth plate and disposed angularly with relation to a radial direction from the center of said hearth plate and at dilferent distances from the center of said hearth plate, whereby said material is moved radially on said hearth plate, a stationary pivot disposed near said discharge conduit and above said hearth plate, a delivering plate pivoted on said pivot, extending until over that one of the surfaces of said hearth plate swept by said vanes which is nearest said discharge conduit, and adapted to assume different angular positions with relation to the radius of said hearth plate passing through said pivot, and means for varying the angular position of said delivering plate, whereby the amount of material delivered from said hearth plate into said discharge conduit may be regulated.

4:. In a retort, a rev-olvable hearth plate, means for rotating said hearth plate about a vertical axis, stationary supports in radial directions above said hearth plate, vanes for guiding the material to be treated carried on said supports and having their lower edges adjacent said hearth plate and disposed angularly with relation to a radial direction and at different distances from the center of said hearth plate with their inner ends directed towards the center of said hearth plate and their outer ends directed towards the periphery of the hearth plate, each of said vanes having its inner end at least as near this center of the hearth plate as the outer end of the vane which is the next nearer said center and its outer end at least as far from this center as'the inner end of the vane which is the next farther from this center.

5. In a retort, a revolvable hearth plate, means for rotating said hearth plate about a vertical axis, a stationary support above said hearth plate, vanes for guiding the material carried on said support and having their lower edges adjacent said hearth plate and disposed angularly with relation to a radial direction and at different distances from the center of said hearth plate, whereby said material is moved radially on said hearth plate, a feeding hopper for the material to be treated having its lower end near and above said hearth plate and offset out of the surfaces of the hearth swept by said vanes, a stationary pivot disposed near said lower end of said hopper, a control plate pivoted on said pivot, extending until over that one of the surfaces of said hearth plate swept by said vanes which is nearest said hopper, and adapted to assume different angular positions with relation to the radius of said hearth plate passing through said pivot, and means for varying the angular position of said control plate, whereby the amount of material supplied from said hopper to said hearth plate may be regulated.

In testimony whereof I have signed my name to this specification.

CHARLES AB-DER-I-IALDEN. 

